Dr.-Ing. Jürgen Fitschen

2018 - 2023        Research Fellow at the IMS

Boehringer Ingelheim Pharma GmbH & Co. KG
Bioprocess Development Biologicals

Binger Strasse 173

55216 Ingelheim am Rhein

Phone +49 7351 54-177970

Mail Dr. Jürgen Fitschen

Research Expertise

  • Large Scale Bioreactors

  • Characterization of Heterogeneities in Aerated Stirred Tank Reactors

  • Characterization of Mixing Time


Publications

[191125]
Title: Experimental analysis of lifelines in a 15,000 L bioreactor by means of Lagrangian Sensor Particles.
Written by: Hofmann, S.; Buntkiel, L.; Rautenbach, R.; Gaugler, L.; Ma, Y.; Haase, I.; Fitschen, J.; Wucherpfennig, T.; Reinecke, S. F.; Hoffmann, M.; Takors, R.; Hampel, U.; Schlüter, M.
in: <em>Chemical Engineering Research and Design</em>. (2024).
Volume: <strong>205</strong>. Number:
on pages: 695-712
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DOI: https://doi.org/10.1016/j.cherd.2024.04.015
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Abstract: This study employs Lagrangian Sensor Particles (LSPs) with a diameter of 40 mm equipped with a pressure sensor to investigate cell lifelines in a 15,000 L stirred tank reactor (STR) with three Elephant Ear impellers. The Stokes number of the LSPs is approx. 0.004 on a macro-scale. The vertical probability of presence, axial velocity profiles, circulation time distributions, and residence time distributions are quantified to analyze single-phase mixing heterogeneities, detect hydrodynamic compartments and conduct a Lagrangian regime analysis. Results reveal a similarly distributed probability of presence in the vertical reactor center but emphasize the LSP’s sensitivity to fluctuating densities. Axial velocity distributions illustrate characteristic impeller-induced flow patterns, and circulation time distributions identify three compartments with comparatively shorter times in the axial center. Residence time distributions exhibit a similar compartmentalized profile. Moreover, the study estimates a potential oxygen deprivation zone for CHO cells in the upper compartment and demonstrates the LSP’s efficacy in characterizing impeller systems. Contrary to literature, the ratio of examined global mixing times to circulation times is 1.0, highlighting macro-scale mixing. The research underscores that LSPs offer crucial insights into industrial-scale STRs, specifically for determining hydrodynamic compartments without having optical access.